Sensitization of photographic emulsions to be developed with p-phenylenediamine developing agents



Patented Nov. 6, 1962 SENSITIZATION F PHOTOGRAFHIC EMULSIGNS TO BE DEVELOEED WITH p-PHENYLENEDI- AMKNE DEVELOPING AGENTS Burt H. Carroll, Rochester, N.Y., assiguor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey N0 Drawing. Filed Nov. 27, 1957, Ser. No. 699,200

12 Claims. (Cl. 96-55) This invention relates to the sensitization of photographic silver halide emulsions which are to be developed with p-phenylenediamine developing agents.

This application is a continuation-in-part of my application Serial No. 642,381, filed February 26, 1957, and now abandoned, which is a continuation-in-part of my application Serial No. 319,615, filed November 8, 1952, now U.S. Patent 2,784,090.

My prior Patent 2,784,090 describes the stabilization with certain organic compounds of mercury, of silver halide emulsions sensitized with onium compounds. Such emulsions may be developed with Elon-hydroquinone developing agents to form black-and-white images, or with p-phenylenediamine developing agents in the presence of color-forming compounds, either in the emulsion or in the developing solution. These color-forming compounds couple with the oxidation product of the pphenylenediamine developing agent to form dye images.

It is known that certain cationic surface-active agents such as N-dodecyl triethyl ammonium bromide and N- dodecyl pyridinium bromide are not effective in increasing the speed of a silver halide emulsion when it is developed with a p-phenylenediamine developing agent (British Patent 566,314).

I have found, however, that the bis-quaternary ammonium salts in which the cationic ammonium group is linked through the nitrogen atom by a bivalent organic radical containing a chain (including a ring) of at least four (and preferably at least seven) atoms, to the nitrogen atom of another quaternary ammonium salt group, are quite effective in increasing the speed of the silver halide emulsion when the emulsion is exposed and developed with a p-phenylenediamine developing agent in the presence of a compound which couples with the oxidation product of the p-phenylenediamine developing agent.

The bis-quaternary ammonium salts used according to my invention are described, for example, in Carroll and Allen U.S. Patent 2,288,226. Typical compounds are:

(1) Decamethylene bis 2 phenylpyramidazoliurnp-toluene sulfonate (2) N,N trimethylenedioxymethylpyridinium perchlorate (3) Hexamethylene-bis-oxymethylpyridinium perchlorate (4) 1,10 decamethylene bis 1,3,5 trimethyl py- 1,4-butylene-bis-pyridinium perchlorate Pentamethylene-bis-pyridinium perchlorate (14) n-Hexylene-bis-pyridinium perchlorate (15) n-Heptylenebis-pyridinium perchlorate The photographic emulsions which I use are of the eveloping-out type and best results have been obtained with gelatino-silver bromoiodide emulsions. However, emulsions of varying halide content may be used.

The emulsions may be chemically sensitized by any of the accepted procedures, in addition to or in combination with the sensitizing with onium compounds. The emulsions may be digested with naturally active gelatin, or sulfur compounds may be added such as those described in Sheppard U.S. Patents 1,574,944 and 1,623,499, and Sheppard and Brigham U.S. Patent 2,410,689.

The emulsions may also be treated with salts of the noble metals such as ruthenium, rhodium, palladium, iridium and platinum, all of which belong to group VH1 of the periodic table of elements and have an atomic weight greater than 100. Representative compounds are ammonium chloropalladate, potassium chloroplatinate and sodium chloropalladite, which are used for sensitizing in amounts below that which produces any substantial fog inhibition, as described in Smith and Trivelli U.S. Patent 2,448,060, and as anti-foggants in higher amounts, as described in Trivelli and Smith U.S. Patents 2,566,- 245 and 2,566,263.

The emulsions may also be chemically sensitized with gold salts as described in Waller and Dodd U.S. Patent 2,399,083, Damschroder U.S. Patent 2,597,856, and Yutzy and Leermakers U.S. Patent 2,597,915. Suitable compounds are potassium chloroaurite, potassium aurithiocyanate, potassium chloroaurate, auric trichlo-ride and 2-aurosulfobenzothiazole methachloride.

The emulsions may also be chemically sensitized with reducing agents such as stannous salts (Carroll U.S. Patent 2,487,850), poiyamines such as diethylene triamine (Lowe and Jones U.S. Patent 2,518,698), polyamines such as spermine (Lowe and Allen U.S. Patent 2,521,- 925), or bis-(,B-aminoethyl) sulfide and its water-soluble salts (Lowe and Jones U.S. Patent 2,521,926).

The bis-quaternary ammonium salts are effective in the presence or absence of optical sensitizing dyes. Both unsensitized emulsions and emulsions sensitized with cyanine or merocyanine dyes or both may be treat-ed with the quaternary ammonium salts according to my invention.

The bis-quaternary ammonium salts may be used in the silver halide emulsion in concentrations ranging from .02 to 4 grams per gram mole of silver halide in the emulsion.

My invention will be further illustrated by reference to the following specific examples:

EXAMPLE 1 A high-speed gelatino-silver bromoiodide emulsion containing 0.24 mole of silver halide per liter was digested with a sulfur compound such as disclosed in Sheppard U.S. Patent 1,574,944, and potassium chloroaurate, and divided into several portions. One portion was used as a control. To a second portion there was added .75 gram per mole of silver halide of compound 7. To a third portion there was added 3 grams per mole of silver halide of 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene. To portions of the latter portion there were added various amounts of compound 7. All of these portions were then coated on film base, chill-set and dried. After exposure in an Eastman-type Ib sensito-meter for second, the films were processed for fifteen minutes in the following solution:

Benzyl alcohol cc 10 4 amino-N-ethyl-N-(fi sulfonamidoethyl)-m-toluidine grams 11 Sodium sulfite (des.) do 2 3 Sodium hexametaphosphate do 2 Sodium carbonate (des.) do 35 Sodium thiocyanate do 0.2 Potassium bromide do 15 Sodium hydroxide do 16 8-arnino-1-naphthol-3,6-disulfonic acid do 10 Water to 1 liter.

The control coating and the coating to which the various addenda had been added were then dried and the results of speed, gamma and fog determinations were found to be as follows:

The speed number used in this table is 100(1-log E), where E is the exposure in meter candle seconds of light of daylight quality, required to produce a developable density of 0.30 greater than fog: thus an increase of 30 units in speed corresponds to double the sensitivity, an increase of 100 units to 10 times, and so on.

These results show that an appreciable speed increase is obtained when the emulsion is developed in a p-phenylcnediamine developer in the presence of a coupler compound. In this case the dye formed by coupling is soluble and is removed from the emulsion during processing but the example illustrates the principle of developing in the presence of a coupling compound.

EXAMPLE 2 A high-speed gelatino-silver bromoiodide emulsion was chemically sensitized with sulfur and gold compounds as in Example 1 and optically sensitized to red light, and a cyan color former added in a manner similar to that described in Example 1 of US. Patent 2,367,531 using a cyan coupler similar to those described in that patent. To various portions of this emulsion the bis-quaternary ammonium salts shown in the following table were added, and the emulsions were coated on a cellulose acetate film support, dried, exposed on an intensity scale sensitometer. and processed as described in Journal of the Society of Motion Picture and Television Engineers, 61, No. 6, December 1953, pages 672 to 676. This processing involves development directly in a color-forming developer containing a p-phenylenediamine developing agent. The results indicated in the following table were obtained:

Compound Grams, AD AS eed mole m m. D

Control Compound 6 2 08 16 Do 4 14 18 Compound l2 2 06 18 Compound 13 2 10 18 Compound 14 2 06 16 Compound 15 4 22 28 In this table AD indicates change in minimum density compared to the control, and A speed indicates change in speed in log E units measured at 0.2 density above fog compared to the control. It will be seen from the table that in every case, the speed is increased when the bis-quaternary ammonium salt is used in the emulsion.

EXAMPLE 3 The use of the following bis-pyridinium compounds in color photography is illustrated in this example.

I. 4,11-diaza-3,12-dioxotetradecane-1,14-bis- (pyridinium perchlorate) 3,14-diaza-2,15-dioxohexadecane-1,16-bis- (pyridinium perchlorate) 7,l4-diaza-6,15-dioxoeicosane-1,20-bis- (pyridinium perchlorate) 12,19-diaza-11,20-dioxotriacontane-1,30-bis- (pyridinium perchlorate) 12,23-diaza-11,24-dioxotetratriacontane-1,34-

bis (pyridinium perchlorate) 5,12-diaza-3,14-dioxa-4,l3-dioxohexadecanel,l6-bis(pyridinium perchlorate) 13,20-diaza-11,22-dioxa-12,21-dioxodotriacontane-1,32-bis(pyridinium perchlorate) 5,12-dioxa-6,1l-dioxohexadecane-l,16-bis- (pyridinium perchlorate) l1,22-dioxa-12,2l-dioxodotriacontane-1,32-bis- (pyridinium perchlorate) A sulfurand gold-sensitized gelatino-silver bromoiodide emulsion was ripened to maximum sensitivity. To this emulsion was added an optical sensitizing dye that extended the light sensitivity to 6000-7000 A. and a hydrophobic cyan color former suitably dispersed in a high boiling organic solvent. A portion of this liquid emulsion received no further treatment; to another portion Was added one of the compounds described below. Both portions were coated on film support, and the dry films were exposed to red light in an intensity scale sensitometer. The exposed films were processed in reversal Color Process 1 and in the 5248 Negative Color Process 2 with the results shown in the following table. Color process 2 was carried out as described by Hanson and Kisner JSMPTE 61, 667701 (1953), for Color Negative Film, Type 5248, involving the steps of color development, fixation, silver bleaching and final fixation.

Color process 1 was carried out at F. as follows:

(1) Negative development minutes 10 (2) Reversal flash exposure. (3) Color development d0 15 (4) Silver bleaching do 8 (5) Fixing do 3 The negative developer had the following composition: Water, 90 F. (32 C.) liters 1.0 Sodium hexametaphosphate grams 2.0 N-methyl p-aminophenol sulfate do 6.0 Sodium sulfite, desiccated do 50.0 Hydroquinone do 6.0 Sodium carbonate, monohydrated do 35.0 Potassium bromide do 2.0 Sodium thiocyanate do 1.5 0.5% solution of 6-nitrobenzimidazole nitrate cc 12.0 0.1% solution of potassium iodide cc 10.0

The color developing solution above had the following composition:

Water, 70 to F. (21 to 27 C.) liters 1.0 Benzyl alcohol cc 6.0 Sodium hexametaphosphate gramsu 2.0 Sodium sulfite, desiccated do 5.0 Trisodium phosphate do 40.0 Potassium bromide do 0.25

enemas The fixing baths above had the following composition:

Water, 80 F. (27 C.) liters 1.0 Sodium thiosulfate, pentahydrate grams 150.0 Sodium bisulfite do 20.0

Table Color Proo- Color Process 1 ess 2 (Reversal) (Negative) Speed Speed Increase Increase E Control Compound V 2.0 g./rn0le AgX Control Compound VI 2.0 gJmole AgX. Control Compound VII 2.0 g./mole AgX Control Compound VIII 4.0 g./mo1e AgX Control Compound IX 2.0 gJrnole AgX 1 Determined by measuring the shift of the reversal dye curve on the Log E axis at a given density below rraxirrum density.

2 Determined by measuring the shift of the negative dye curve on the Log E axis at a given density above minimum density.

p-Phenylenediamine developers other than those listed in the examples above may be employed in my process. For example, developers such as N,N-diethyl-p-phenylenediamine, N,N-dimethyl-p-phenylenediamine, Z-amino- S-di-ethyla-minotoluene hydrochloride, 4-amino-N-ethyl- N(B-methanesulfonamidoethyl)-aniline and other similar developers may be employed.

The couplers which are used in my process may be incorporated either in the developing solution as described, for example, in US. Patents 1,969,479, 2,271,- 238 and 2,362,598, or they may be incorporated in the emulsion layer as described, for example, in US. Patents 2,298,443, 2,367,531, 2,423,730 and 2,600,788. The color-forming compounds described in these patents are suitable for use according to my invention.

The silver halide emulsions containing the bis-quaternary ammonium salts may be silver bromide, silver iodide, silver chloride or mixed silver halide emulsions. The dispersing agent for the silver halide may be gelatin or other suitable colloidal material such as collodion, albumen, cellulose derivatives or synthetic resins.

It will be understood that I contemplate as included within my invention all modifications and equivalents falling within the scope of the appended claims.

I claim:

1. A light-sensitive silver halide emulsion sensitized 7 with a bis-quaternary ammonium salt a quaternary ammonium salt group of which is linked through its quaternary nitrogen atom directly to the quaternary nitrogen atom of the other quaternary ammonium salt group, by a linear chain of at least four atoms, said emulsion containing a coupler compound of the class consisting of phenolic and S-pyra-zoione coupler compounds capable of coupling with the oxidation product of a p-phenylenediamine silver halide developing agent to form a dye.

2. A light-sensitive silver halide emulsion sensitized with a bis-quaternary ammonium salt a quaternary ammonium salt group of which is linked through its quaternary nitrogen atom directly to the quaternary nitrogen atom of the other quaternary ammonium salt group, by a linear chain of at least four atoms, said emulsion containing a S-pyrazolone coupler compound capable of coupling with the oxidation product of a p-phenylenediamine silver halide developing agent to form a dye.

3. A light-sensitive silver halide emulsion sensitized with a bis-quaternary ammonium salt a quaternary ammonium salt group of which is linked through its quaternary nitrogen atom directly to the quaternary nitrogen atom of the other quaternary ammonium salt group, by a linear chain of at least four atoms, said emulsion containing a phenolic coupler compound capable of coupling with the oxidation product of a p-phenylenediamine silver halide developing agent to form a dye.

4. A method of increasing the speed of a gelatino silver halide emulsion which comprises sensitizing said emulsion with a bis-quaternary ammonium salt a quaternary ammonium salt group of which is linked through its quaternary nitrogen atom directly to the quaternary nitrogen atom of the other quaternary ammonium salt group, by means of a linear chain of at least four atoms, exposing said emulsion and developing it with a p-phenylenediamine silver halide developing agent in the presence of a coupler compound of the class consisting of phenolic and S-pyrazolone coupler compounds capable of coupling with the oxidation product of said developing agent to form a dye, thereby forming a dye image in the emulsion layer in the region of development.

5. A method of increasing the speed of a gelatino silver halide emulsion which comprises sensitizing said emulsion with a bis-quaternary ammonium salt a quaternary ammonium salt group of which is linked through its quaternary nitrogen atom directly to the quaternary nitrogen atom of the other quaternary ammonium salt group, by means of a linear chain of at least four atoms, exposing said emulsion and developing it with a p-phenylenediamine silver halide developing agent in the presence of a phenolic coupler compound capable of coupling with the oxidation product of said developing agent to form a dye, thereby forming a dye image in the emulsion layer in the region of development.

6. A method of increasing the speed of a gelatino silver halide emulsion which comprises sensitizing said emulsion with a bis-quaternary ammonium salt a quaternary ammonium salt group of which is linked through its quaternary nitrogen atom directly to the quaternary nitrogen atom of the other quaternary ammonium salt group, by means of a linear chain of at least four atoms, exposing said emulsion and developing it with a p-phenylenediamine silver halide developing agent in the presence of a S-pyrazoline coupler compound capable of coupling with the oxidation product of said developing agent to form a dye, thereby forming a dye image in the emulsion layer in the region of development.

7. The proces of claim 4 wherein the coupler compound is present in the emulsion prior to exposure.

8. The method of claim 4, in which the pyridinium salt is decamethylene-bis-Z,6-dimethylpyridinium perchlorate.

9. The method of claim 4, in which the pyridinium salt is tetradecamethylene-bis-pyridinium perchlorate.

10. Themethod of claim 4, in which the pyrldim'um salt is decamethylene-bis-pyridinlurn bromide.

11. The method of claim 4, in which the pyridinium salt is decamethylene-bis-Z-methyl-S-ethylpyridinium perchlorate.

. 12. The method of claim 4, in which the pyridinium salt is dccamethylene-bis-oxymethylpyridinium perchlorate.

References (Iited in the file of this patent UNITED STATES PATENTS McQueen Apr. 23, Carroll et a1. June 30, Murray -Jan. 14, Allen et al. May 7, Carroll Mar. 23, Land Dec. 28,

Piper May 12, 

1. A LIGHT-SENSITIVE SILVER HALIDE EMULSION SENSITIZED WITH A BIS-QUATERNARY AMMONIUM SALT A QUATERNARY AMMONIUM SALT GROUP OF WHICH IS LINKED THROUGH ITS QUATERNARY NITROGEN ATOM DIRECTLY TO THE QUATERNARY NITROGEN ATOM OF THE OTHER QUATERNARY AMMONIUM SALT GROUP, BY A LINEAR CHAIN OF AT LEAST FOUR ATOMS, SAID EMULSION CONTAINING A COUPLER COMPOUND OF THE CLASS CONSISTING OF PHENOLIC AND 5-PYRAZOLONE COUPLER COMPOUNDS CAPABLE OF COUPLING WITH THE OXIDATION PRODUCT OF A P-PHENYLENEDIAMINE SILVER HALIDE DEVELOPING AGENT TO FORM A DYE. 